IEC TC106. Standards for the Assessment of Human Exposure to Electric, Magnetic, and Electromagnetic Fields, 0 to 300 GHz

Transcription

1 International Electrotechnical Commission IEC TC106 Standards for the Assessment of Human Exposure to Electric, Magnetic, and Electromagnetic Fields, 0 to 300 GHz R. C. Petersen Chairman

2 Secretariat and Officers Secretariat: Canada IEC Technical Officer Mr. Remy Baillif Chairman: Mr. Ronald C. Petersen (US) Secretary: Monsieur Michel Bourdages (CA) Assistant Secretary: Mr. Thomas FISCHER (DE)

3 TC-106 Participating Countries Australia Austria Belgium Canada China Denmark Finland France Germany Greece Ireland Italy Japan Korea (Republic of) Mexico Netherlands Norway Poland Russian Federation South Africa Spain Sweden Switzerland Turkey United Kingdom United States

4 Liaisons CENELEC: ICNIRP: (European Committee for Electrotechnical Standardization) TC106X (International Commission on Non-Ionizing Radiation Protection) IEC TC 27: Industrial electro-heating equipment IEC TC 77: Electromagnetic compatibility IEC TC 78: Live [powerline] working IEC TC 85: Measuring equipment for electrical and EM quantities CISPR/A: Radio interference measurements and statistical techniques IEEE ICES: TC34 SC2/P62209 Part 2 (Category D Liaison) WHO: EMF Project

5 Scope of Work Standardization of measurement and calculation methods to asses human exposure to electric, magnetic and electromagnetic fields. The task includes: - characterization of the electromagnetic environments with regard to human exposure - measurement methods; instrumentation and procedures - calculation methods - assessment methods for exposure produced by specific sources (in so far as this task is not carried out by specific product committees) - basic standards for other sources - assessment of uncertainties

6 Scope of Work (Continued) The scope of TC106 covers the frequency range from 0 to 300 GHz; TC106 standards can be used to assess compliance with contemporary safety guidelines and standards such as ICNIRP* and IEEE**. Excluded are: - the establishment of exposure limits (basic restrictions and reference levels) - mitigation methods (which have to be dealt with by the relevant product committees) * International Commission on Non-Ionizing Radiation Protection ** Institute of Electrical and Electronics Engineers

7 Basic Restrictions and Derived Limits Basic restrictions: Exposure restrictions that are based on established adverse health effects that incorporate appropriate safety factors and are expressed in terms of the specific absorption rate (100 khz to 3-10 GHz), or incident power density (3-10 GHz to 300 GHz). Specific absorption rate (SAR) The time derivative of the incremental energy absorbed by (dissipated in) an incremental mass contained in a volume element of given density. The SI unit of SAR is the watt per kilogram (W/kg).

8 Basic Restrictions and Derived Limits Specific absorption rate (continued) The basic restrictions found in most contemporary RF safety standards and guidelines are as follows: Uniform exposure (e.g., antenna far-field) 0.4 W/kg (exposure in controlled environmentsoccupational exposure) and 0.08 W/kg (general public) averaged over the mass of the body Localized exposure (e.g., mobile phone) 2W/kg (exposure in controlled environmentsoccupational exposure) and 10 W/kg (general public) averaged over any 10 g of tissue in the shape of a cube (IEEE)

9 Basic Restrictions and Derived Limits Derived limits (maximum permissible exposure values) The highest rms or peak electric or magnetic field strengths, their squares, or the plane-wave equivalent power densities associated with these fields, or the induced and contact currents to which a person may be exposed without incurring an established adverse health effect and with an acceptable margin of safety. The MPEs are derived or estimated from the basic restrictions. If an exposure is proven to be below the basic restrictions, the MPE can be exceeded. MPEs are sometimes called reference levels, derived limits or investigation levels.

10 Working Groups and Projects Working Group 1 Measurement and calculation methods for low frequency (0 to 100 khz) electric and magnetic fields and induced currents Projects : Methods for calculating induced current density and electric fields in the human body - Part 1: General (IEC Standard) - Part 2: Magnetic fields-2d models (IEC Standard) - Part 3: Electric Fields (New Work Item)

11 Working Groups and Projects Working Group 2 Characterization of low frequency electric and magnetic fields from specific devices Projects 62233: Measurement of electric and magnetic fields of domestic appliances with regard to human exposure (IEC Standard) 62110: Measurement procedures for electric and Magnetic fields generated by AC power lines with regard to human exposure (ANW)

12 Working Groups and Projects Working Group 3 Measurement and assessment of high frequency (approximately 100 khz to 300 GHz) electromagnetic fields Project 62334: Technical report on the measurement and assessment of human exposure to high frequency (9 khz to 300 GHz) electromagnetic fields. It will cover quantities that can be directly measured, notably electrical and magnetic field strength but includes also the measurement of current and assessment of internal quantities that form the basis for protection guides. (Similar to IEEE C95.3)

13 Working Groups and Projects Working Group 4 Characterization of high frequency electromagnetic fields and specific absorption rate (SAR) produced by specific sources Project 62209: Human exposure to radio frequency fields from hand-held and body-mounted wireless communication devices Human models, instrumentation, and procedures

14 Working Groups and Projects Working Group 4 (Continued) Project (Continued) - Part 1: Hand-held mobile wireless communication devices (IEC Standard) - Part 2: Procedure to determine the SAR for two-way radios, wireless palmtop terminals, wireless desktop terminals, and wireless body-mounted devices including accessories and multiple transmitters in the frequency band 30 MHz - 6 GHz (CD1)

15 Working Groups and Projects Working Group 4 (Continued) Project 62232: Determination of RF fields in the vicinity of mobile communication base stations for the purpose of evaluating human exposure (Pre CD) This standard will describe measurement and calculation methods used to evaluate RF fields from mobile communication base stations with the objectives of evaluating compliance of these stations with appropriate international standards and guidelines and national regulations on limiting human exposure to RF fields.

16 Working Groups and Projects Working Group 4 (Continued) Project P62369: Assessment of human exposure to electromagnetic fields in the frequency range of GHz - Part 1: Electronic article surveillance systems, RFID and similar systems (CD1)* - Part 2: Alarms, asset tracking, telecommand and control and similar short range low power radio devices (ANW) *Moved from CENELEC (50357)

17 Working Groups and Projects Working Group 5 Generic standards: general application and common practices Projects P62311: Generic product standard to demonstrate compliance of electrical and electronic apparatus with the basic restrictions related to human exposure to electromagnetic fields (0 Hz-300 GHz) (NCD)

18 62232-Wireless Base Stations Technical Challenge

19 62232-Wireless Base Stations Scope-Part 1 (Draft) Measurement methods and analytical techniques to identify levels of RF fields from a single radio base station (RBS) used for wireless telecommunications with one or more antennas. At present, Part 1 does not include measurement and computation methods for multiple RBS locations nor for other RF transmitters that may be present at the point of observation.

20 62232-Scope (Continued) Assessments are based on in-situ field measurements or computations at defined locations over a period of time. The standard will enable assessments based on worse case parameters such as maximum radiated power during the peak of wireless transmission activity and over an extended period of time where such maximum conditions might occur. The intent of the standard is to provide: Information to communicate to the public to address concerns. An evaluation of field strength to facilitate comparison with relevant compliance limits.

21 62232-Wireless Base Stations Instrumentation Technique Measurement Problem: Purpose Region Type Uncertainty Measurement Solution: Method Protocol Report

22 62232-Wireless Base Stations Environment complexity

23 62232-General Outline Source-environment regions Near field Far field Scatters None Single Multiple Well-characterized, non-characterized

24 62232-General Outline Selecting the appropriate strategy Purpose of survey (e.g., community driven) Level of approach Accuracy and availability of source data Where when to evaluate Situations that methods that suggest measurement/calculation Measurement methods Instrumentation (broadband/narrowband) Pre-assessment considerations Uncertainty

25 62232-General Outline Computational methods Ray-tracing (applicability/strength/weaknesses) Cylindrical model (applicability/strength/weaknesses) Full-wave analysis, e.g., Method of Moments, NEC, (applicability/strength/weaknesses) SAR evaluation Data analysis Evaluation result Uncertainty assessment

26 62232-General Outline Report Purpose (e.g., community concern, compliance, occupational safety) Minimum information required Methods for recording data (e.g., manual, analog, digital) Additional information required System parameters (e.g., cable loss, bandwidth, test-antenna gain)

27 62209 Portable Wireless Devices Part 1 The objective of this standard is to specify the measurement method for demonstration of compliance with the specific absorption rate (SAR) limits for such devices. This International Standard applies to any electromagnetic field (EMF) transmitting device intended to be used with the radiating part of the device in close proximity to the human head and held against the ear, including mobile phones, cordless phones, etc. The frequency range is 300 MHz to 3 GHz.

28 62209 Portable Wireless Devices Part 1 (Continued) The SAR is determined from measurements of the E- field (E) in an anatomically-correct phantom model (liquid-filled dielectric shell) of the human head using a robotically-scanned miniature E-field probe. The liquid within the shell has electrical properties that simulate human brain tissue. The SAR is determined from the relationship between E and the tissue properties, i.e., SAR = σ E 2 /ρ where σ is the liquid conductivity and ρ is the density

29 62209 General Outline Part 1 (Continued) Measurement system specifications General requirements Phantom specifications (shell and liquid) Specifications of the SAR measurement equipment Scanning system specifications Device holder specifications Measurement of liquid dielectric properties

30 62209 General Outline Part 1 (Continued) Protocol for SAR assessment Measurement preparation Tests to be performed Measurement procedure Post-processing of SAR measurement data Uncertainty estimation General considerations Components contributing to uncertainty Uncertainty estimation

31 62209 General Outline Part 1 (Continued) Measurement report General Items to be recorded in the test report Annexes Phantom specifications Calibration (linearity, isotropy, sensitivity) of the measurement instrument and uncertainty estimation Post processing techniques and uncertainty estimation

32 62209 General Outline Part 1 (Continued) SAR measurement system validation Interlaboratory comparisons SAR measurement system validation Inter-laboratory comparisons Definition of a phantom coordinate system and the device under test coordinate system Validation dipoles Flat phantom

33 62209 General Outline Part 1 (Continued) Recommended recipes for phantom head tissueequivalent liquids Measurement of the dielectric properties of liquids and uncertainty estimation NOTE Part 1 of IEC is now being revised the frequency range will be extended from 3 GHz to 6 GHz

34 62209 Part 2 (New Work Item) Title: Procedure to determine the Specific Absorption Rate (SAR) in the head and body for 30 MHz to 6 GHz Handheld and Body-Mounted Devices used in close proximity to the Body. This standard will provide a reproducible and conservative measurement methodology for determining compliance with the SAR limits for portable and mobile wireless devices intended to be used with the radiating part of the device closer than 20 cm to the human body. The hand will be modeled for handheld devices only and will not be modeled if the device is intended to be used next to the head or on the body.

35 62209 Part 2 The standard applies to devices which are used at a location near the human body, i.e. when held in the hand or in front of the face, or mounted on the body as stand alone devices, transmitting accessories, or embedded in garments. It is applicable for radio frequency exposure in the frequency range 30 MHz to 6 GHz and may be used to assess concurrent exposures from multiple radio sources. The types of devices include but are not limited to mobile telephones, cordless telephones, cordless microphones, auxiliary broadcast devices and radio parts of various sizes of computers. Expected Completion: 2008

36 Conclusion IEC TC-106 develops standards for assessing human exposure to electric, magnetic and electromagnetic fields over the frequency range of 0 Hz to 300 GHz. The standards address products not covered by other IEC standards and generic standards that can be used for conformity assessment with regard to the basic restrictions and derived limits of contemporary RF safety standards, guidelines and regulations. The committee works closely with other international committees to ensure harmonization.

37 Thank You